Biomedical subjects

R B Jenkins

Publications and source records attributed to R B Jenkins.

At least 37 records · Page 2Linked to original sources

PubMed2000

Mapping of the chromosome 19 q-arm glioma tumor suppressor gene using fluorescence in situ hybridization and novel microsatellite markers.

Allelic loss of chromosome arm 19q is a frequent event in human diffuse glioma, suggesting the presence of a tumor suppressor gene. Previous loss of heterozygosity (LOH) analyses have mapped this gene to a 1.4-megabase interval, between the genetic markers D19S412 and STD. Further narrowing of this interval has been limited by the resolution of mapped polymorphic markers. In the present study, we have used genomic clones mapped to 19q as fluorescence in situ hybridization (FISH) probes to map the breakpoints of 13 gliomas with 19q13.3 deletion boundaries. In addition, we have developed three new polymorphic microsatellite markers (D19S1180, D19S1181, and D19S1182) that map between D19S412 and STD and have used these new markers to identify two gliomas with small deletions between the D19S412 and STD markers. Collectively, these data suggest that the region of common deletion may be as narrow as 150 kb and should facilitate future efforts to identify the glioma 19q tumor suppressor gene.

Chromosome Deletion↗

PubMed2000

Structure and analysis of the human dimethylglycine dehydrogenase gene.

Dimethylglycine dehydrogenase (DMGDH; E.C. 1.5.99.2) is an enzyme involved in the catabolism of choline, catalyzing the oxidative demethylation of dimethylglycine (DMG) to form sarcosine. Subsequently, sarcosine dehydrogenase (SDH; E.C. 1.5.99.1) converts sarcosine to glycine via a similar reaction. Both enzymes are found as monomers in the mitochondrial matrix, and both contain 1 mol of covalently bound flavin adenine dinucleotide. DMGDH and SDH also utilize a noncovalently bound folate coenzyme that receives the "1-carbon" groups that are removed by DMGDH and SDH, forming "active formaldehyde." We have recently described a new inborn error of metabolism of DMGDH characterized by an unusual fish-like body odor. To augment our study of this new disorder, we have isolated two human genomic clones that together contain 16 exons of coding sequence for the hDMGDH gene. Fluorescent in situ hybridization analysis of the hDMGDH gene indicates that it is found on chromosome 5q12.2-q12.3. In addition, several polymorphisms have been identified in the hDMGDH cDNA sequence. Population analysis of two Ser/Pro polymorphisms found 367 amino acids apart reveals a skew of alleles, with the haplotypes Ser/Pro or Pro/Ser (79%) overrepresented compared to the number of Ser/Ser or Pro/Pro alleles observed. Possible functional consequences of these findings are discussed. Characterization of the gene structure for hDMGDH will aid in the study of patients with inherited defects of this enzyme.

Alleles↗

PubMed2000

Comparative genomic hybridization of medulloblastomas and clinical relevance: eleven new cases and a review of the literature.

Medulloblastomas are highly malignant primitive neuroectodermal tumors of the cerebellum that display a wide variety of histopathological patterns. However, these patterns do not provide an accurate prediction of clinical-biological behavior and no satisfactory morphological grading system has ever been presented. Genetic alterations may provide additional diagnostic information and allow clinically relevant subgrouping of primitive neuroectodermal tumors. We examined 10 medulloblastomas and one medulloblastoma cell line. One amplification site on chromosome 8q24 was detected in the cell line corresponding to the known amplification of the c-myc gene in this cell line. The gain of 2p21-24 in two tumors was shown to represent amplification of the N-myc gene by Southern blot hybridization and fluorescence in situ hybridization. The data show that the isochromosome 17 can be recognized using comparative genomic hybridization (CGH) by the typical combination of loss of 17p combined with gain of 17q. No specific pattern of genetic alterations could be linked to the clinical behavior of the tumors. We have compared our results with previous CGH studies on medulloblastomas.

Adolescent↗

PubMed2000

The development of a multitarget, multicolor fluorescence in situ hybridization assay for the detection of urothelial carcinoma in urine.

The purpose of this study was to develop a multitarget, multicolor fluorescence in situ hybridization (FISH) assay for the detection of urothelial carcinoma (UC) in urine specimens. Urinary cells obtained from voided urine specimens of 21 patients with UC and 9 normal donors were analyzed with nine different centromere enumeration probes and a single locus-specific indicator probe to determine an optimal set of FISH probes for UC detection. The four probes with the greatest sensitivity for UC detection were then labeled with a unique fluorophore and combined into a single probe set. The probes with the greatest combined sensitivity for UC detection were CEP3, CEP7, CEP17, and the 9p21 (P16) LSI. This probe set was used to evaluate urine specimens acquired from 179 patients for prospective testing (46 with biopsy-proven UC). FISH slides were evaluated by scanning the slide for cells with nuclear features suggestive of malignancy and assessing the FISH signal pattern of these cells for polysomy (ie, gains of two or more different chromosomes). A receiver operator characteristic curve revealed that a cutoff of 5 cells with polysomy as the positive criterion for cancer resulted in an overall sensitivity of 84.2% for patients with biopsy-proven UC and a specificity of 91.8% among patients with genitourinary disorders but no evidence of UC. This study demonstrates that a multitarget, multicolor FISH assay containing centromeric probes to chromosomes 3, 7, and 17 and a locus-specific probe to band 9p21 has high sensitivity and specificity for the detection of UC in voided urine specimens.

Aneuploidy↗

PubMed2000

Amplification of the platelet-derived growth factor receptor-A (PDGFRA) gene occurs in oligodendrogliomas with grade IV anaplastic features.

Activation of the platelet-derived growth factor (PDGF) signaling system has been implicated in the development and malignant progression of diffuse gliomas. Overexpression of PDGF system components, particularly the alpha subtype receptor (PDGFRA), is common in glial tumors, and PDGFRA gene amplification has been reported in glioblastomas. In order to address the incidence of PDGFRA gene amplification in a broad set of diffuse gliomas, we used Southern and fluorescence in situ hybridization (FISH) analyses to examine 167 astrocytic gliomas (20 grade III and 147 grade IV), 41 anaplastic oligodendrogliomas, and 29 anaplastic oligoastrocytomas. PDGFRA gene amplification was identified in 4 anaplastic oligodendrogliomas and in a single case of anaplastic oligoastrocytoma, but in none of the malignant astrocytomas. Each of the 5 tumors with PDGFRA amplification displayed features generally associated with grade IV malignancy in astrocytic tumors. Consequently, our data indicate that this gene alteration is restricted to tumors having oligodendroglial differentiation and highly anaplastic features.

Blotting, Southern↗

PubMed2000

Alterations of chromosome arms 1p and 19q as predictors of survival in oligodendrogliomas, astrocytomas, and mixed oligoastrocytomas.

PURPOSE: A recent report suggests that alterations of chromosome arms 1p and 19q are associated with chemotherapeutic response and overall survival in anaplastic oligodendroglioma patients treated with procarbazine, lomustine, and vincristine chemotherapy. We set out to further clarify the diagnostic and prognostic implications of these alterations in a broader set of diffuse gliomas, including astrocytic neoplasms and low-grade oligodendrogliomas. PATIENTS AND METHODS: Fluorescence in situ hybridization (FISH) signals from DNA probes mapping to 1p and 19q common deletion regions were enumerated in 162 diffuse gliomas (79 astrocytomas, 52 oligodendrogliomas, and 31 mixed oligoastrocytomas), collected as part of an ongoing prospective investigation of CNS tumors. RESULTS: The oligodendroglial phenotype was highly associated with loss of 1p (P =.0002), loss of 19q (P <.0001), and combined loss of 1p and 19q (P <.0001). Combined loss of 1p and 19q was identified as a univariate predictor of prolonged overall survival among patients with pure oligodendroglioma (log-rank, P =.03) and remained a significant predictor after adjusting for the effects of patient age and tumor grade (P <.01). This favorable association was not evident in patients with astrocytoma or mixed oligoastrocytoma. CONCLUSION: Combined loss of 1p and 19q is a statistically significant predictor of prolonged survival in patients with pure oligodendroglioma, independent of tumor grade. Given the lack of this association in patients with astrocytic neoplasms and the previously demonstrated chemosensitivity of oligodendrogliomas, a combined approach of histologic and genotypic assessment could potentially improve existing strategies for patient stratification and management.

Adolescent↗

PubMed2000

Characterization of an ovarian carcinoma cell line resistant to cisplatin and flavopiridol.

Flavopiridol, the first inhibitor of cyclin-dependent kinases to enter clinical trials, has shown promising antineoplastic activity and is currently undergoing Phase II testing. Little is known about mechanisms of resistance to this agent. In the present study, we have characterized an ovarian carcinoma cell line [OV202 high passage (hp)] that spontaneously developed drug resistance upon prolonged passage in tissue culture. Standard cytogenetic analysis and spectral karyotyping revealed that OV202 hp and the parental low passage line OV202 shared several marker chromosomes, confirming the relatedness of these cell lines. Immunoblotting demonstrated that OV202 and OV202 hp contained similar levels of a variety of polypeptides involved in cell cycle regulation, including cyclin-dependent kinases 2 and 4; cyclins A, D1, and E; and proliferating cell nuclear antigen. Despite these similarities, OV202 hp was resistant to flavopiridol and cisplatin, with increases of 5- and 3-fold, respectively, in the mean drug concentrations required to inhibit colony formation by 90%. In contrast, OV202 hp and OV202 displayed indistinguishable sensitivities to oxaliplatin, paclitaxel, topotecan, 1,3-bis(2-chloroethyl)-1-nitrosourea, etoposide, doxorubicin, vincristine, and 5-fluorouracil, suggesting that the spontaneously acquired resistance was not attributable to altered P-glycoprotein levels or a general failure to engage the cell death machinery. After incubation with cisplatin, whole cell platinum and platinum-DNA adducts measured using mass spectrometry were lower in OV202 hp cells than OV202 cells. Similarly, after flavopiridol exposure, whole cell flavopiridol concentrations measured by a newly developed high performance liquid chromatography assay were lower in OV202 hp cells. These data are consistent with the hypothesis that acquisition of spontaneous resistance to flavopiridol and cisplatin in OV202 hp cells is due, at least in part, to reduced accumulation of the respective drugs. These observations not only provide the first characterization of a flavopiridol-resistant cell line but also raise the possibility that alterations in drug accumulation might be important in determining sensitivity to this agent.

Antineoplastic Agents↗

PubMed2000

A comparison of cytology and fluorescence in situ hybridization for the detection of urothelial carcinoma.

PURPOSE: We determine the relative sensitivities of cytology and fluorescence in situ hybridization (FISH) for the detection of urothelial carcinoma. MATERIALS AND METHODS: A mixture of fluorescent labeled probes to the centromeres of chromosomes 3, 7 and 17, and band 9p21 (P16/CDKN2A gene) was used to assess urinary cells for chromosomal abnormalities indicative of malignancy. A total of 280 urine specimens from 265 patients, including 150 with a history of urothelial carcinoma and 115 without a history of urothelial carcinoma, were analyzed. FISH analysis was performed without prior knowledge of clinical findings, that is biopsy, cystoscopy and cytology results. A positive result was defined as 5 or more urinary cells with gains of 2 or more chromosomes. RESULTS: A total of 75 biopsies showed urothelial carcinoma at FISH analysis among the 265 patients. The sensitivity of urine cytology for pTa (36 cases), pTis (18) and pT1-pT4 (15) tumors was 47%, 78% and 60%, respectively, for an overall sensitivity of 58%. The sensitivity of FISH for pTa (37 cases), pTis (17) and pT1-pT4 (19) tumors was 65%, 100% and 95%, respectively, for an overall sensitivity of 81%. FISH was significantly more sensitive than cytology for pTis (p = 0.046), pT1-pT4 (p = 0.025), grade 3 (p = 0.003) and all tumors (p = 0.001). The specificity of cytology and FISH among patients without cystoscopic evidence of urothelial carcinoma and no history of urothelial carcinoma was 98% and 96%, respectively (p = 0.564). CONCLUSIONS: The sensitivity of FISH for the detection of urothelial carcinoma is superior to that of cytology, and the specificity of FISH and cytology for urothelial carcinoma are not significantly different. Further prospective studies are required but FISH has the potential to improve significantly the management of urothelial carcinoma.

Centromere↗

PubMed1999

Clinical significance of alterations of chromosome 8 in high-grade, advanced, nonmetastatic prostate carcinoma.

BACKGROUND: Chromosome 8 alterations, including loss of 8p21-22 and gain of 8q24, are commonly observed in prostate carcinoma. We examined whether these alterations are associated with poor prognosis in prostate cancer. METHODS: We used dual-probe fluorescence in situ hybridization and DNA probes for 8p22 (lipoprotein lipase gene), centromere 8 (8cen), and 8q24 (c-myc gene) to determine the corresponding copy numbers in tumor samples from 144 patients with high-grade, advanced (stage III) prostate carcinoma. Cox models were used for multivariate analysis of systemic progression or patient death from prostate cancer. All statistical tests are two-sided. RESULTS: We classified the 8p22, 8cen, and c-myc copy number as normal, loss, and gain. An additional increase (AI) category of c-myc relative to the centromere copy number (i.e., overrepresentation and amplification of c-myc) was also used. Alterations of 8p22 were not statistically significantly associated with either systemic progression or patient death. Alterations of c-myc were associated with both systemic progression (P =.024) and patient death (P =.039); AI of c-myc showed the poorest outcome. We also evaluated the prognostic relevance of the combined 8p22-8cen-c-myc loci anomaly pattern for the following six patterns: normal-normal-normal, loss-any 8cen-normal, loss-gain-gain, gain-gain-gain, non-loss-any 8cen-AI, and loss-any 8cen-AI, where any 8cen is normal, loss, or gain of the chromosome 8 centromere. Patients with the loss-any 8cen-AI pattern had earlier systemic progression (P =.009) and earlier cause-specific death (P =.013) than did patients with other patterns. Multivariate analyses demonstrated that the loss-any 8cen-AI pattern was an independent risk factor for systemic progression (P<.001) and cause-specific death (P =.002). CONCLUSIONS: Genetic alterations of chromosome 8 appear to accumulate in parallel with the progression of prostate carcinomas. AI of the c-myc gene, especially with loss of 8p22, appears to be associated with poor patient prognosis.

Centromere↗

PubMed1999

Clinicopathologic study of 85 similarly treated patients with anaplastic astrocytic tumors. An analysis of DNA content (ploidy), cellular proliferation, and p53 expression.

BACKGROUND: The biologic behavior of anaplastic (World Health Organization Grade III) astrocytomas and oligoastrocytomas is highly variable, ranging from rapid progression to prolonged survival. It is difficult to predict the outcome of an individual patient based on morphology alone. METHODS: To determine the prognostic value of commonly used clinicopathologic markers, we reviewed our experience with 85 similarly treated patients enrolled in 3 North Central Cancer Treatment Group high grade glioma protocols. The pathology was comprised exclusively of primary anaplastic astrocytic tumors (66 astrocytomas and 19 oligoastrocytomas). Variables examined included patient age, morphologic type, preoperative performance score, extent of surgery, solitary versus multiple mitoses, DNA flow cytometric and image morphometric parameters, and expression of proliferating cell nuclear antigen, MIB-1, and p53 expression. RESULTS: The study was comprised of 48 men and 37 women ranging in age from 14-79 years (median age, 47 years). Overall survival ranged from <1 month to >12 years (median, 21.6 months). Statistical analyses revealed that age accounted for the majority of this extensive variability in survival. The median survival times were 65. 5 months, 22.1 months, and 4.4 months, respectively, for the groups <40 years, 40-59 years, and >/=60 years, respectively (P < 0.0001). On univariate analyses, aneuploidy by flow cytometry and a low performance score also predicted a better survival (P values of 0.04 and 0.009, respectively). Statistical trends predicting a better survival were observed for patients with a solitary mitosis and p53 immunopositivity. However, only patient age remained significant in multivariate models. CONCLUSIONS: In a small but relatively uniformly treated cohort of patients with anaplastic astrocytomas and oligoastrocytomas, patient age was associated strongly and inversely with overall survival. Once patient age was taken into account, the clinical and pathologic markers tested appeared to be of limited prognostic value.

Adolescent↗

PubMed1999

Localization of common deletion regions on 1p and 19q in human gliomas and their association with histological subtype.

Allelic alterations of chromosomes 1 and 19 are frequent events in human diffuse gliomas and have recently proven to be strong predictors of chemotherapeutic response and prolonged survival in oligodendrogliomas (Cairncross et al., 1998; Smith et al., submitted). Using 115 human diffuse gliomas, we localized regions of common allelic loss on chromosomes 1 and 19 and assessed the association of these deletion intervals with glioma histological subtypes. Further, we evaluated the capacity of multiple modalities to detect these alterations, including loss of heterozygosity (LOH), fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH). The correlation coefficients for detection of 1p and 19q alterations, respectively, between modalities were: 0.98 and 0.87 for LOH and FISH, 0.79 and 0.60 for LOH and CGH, and 0.79 and 0.53 for FISH and CGH. Minimal deletion regions were defined on 19q13.3 (D19S412-D19S596) and 1p (D1S468-D1S1612). Loss of the 1p36 region was found in 18% of astrocytomas (10/55) and in 73% (24/33) of oligodendrogliomas (P < 0.0001), and loss of the 19q13.3 region was found in 38% (21/55) of astrocytomas and 73% (24/33) of oligodendrogliomas (P = 0.0017). Loss of both regions was found in 11% (6/55) of astrocytomas and in 64% (21/33) of oligodendrogliomas (P < 0.0001). All gliomas with LOH on either 1p or 19q demonstrated loss of the corresponding FISH probe, 1p36 or 19q13.3, suggesting not only locations of putative tumor suppressor genes, but also a simple assay for assessment of 1p and 19q alterations as diagnostic and prognostic markers.

Astrocytoma↗

PubMed1999

Cloning of a human ortholog (RPH3AL) of (RNO)Rph3al from a candidate 17p13.3 medulloblastoma tumor suppressor locus.

Allelic loss of 17p13.3 is observed in approximately 40% of medulloblastomas, suggesting the presence of a tumor suppressor gene in this region. Deletion mapping has defined a region of common loss flanking the telomeric marker D17S34, and a recent report delineated a 9-kb homozygous deletion within the D17S34 locus in one such tumor. Using cDNA selection, we have identified a transcript spanning this deletion, designated (HSA)RPH3AL (rabphillin-3A-like), based on its 77% overall amino acid identity with a recently cloned rat gene, (RNO)Rph3al (originally termed Noc2), a gene putatively involved in regulated endocrine exocytosis through its interactions with the cytoskeleton. We determined the exon-intron boundaries of RPH3AL and screened the coding region for mutations by direct sequencing in DNA extracted from 33 tumor samples with allelic loss of 17p13, including 10 medulloblastoma, 14 follicular thyroid cancer (FTC), and 9 ovarian cancer specimens. No mutations were identified. Thus, despite its location in a homozygously deleted 17p13.3 locus, it is unlikely that RPH3AL is a gene involved in the oncogenesis of medulloblastoma, FTC, or ovarian cancer.

Adaptor Proteins, Signal Transducing↗

PubMed1999

Localization of PS6K to chromosomal region 17q23 and determination of its amplification in breast cancer.

The application of comparative genomic hybridization to the analysis of genetic abnormalities in breast carcinoma has consistently revealed that chromosome region 17q22-24 is a frequent site of gene amplification in this type of cancer. As part of an examination of expressed sequence tags for novel amplified genes in this region, we identified PS6K amplifications in both breast tumor tissues and cell lines. PS6K was localized to 17q23 and encodes a serine-threonine kinase whose activation is thought to regulate a wide array of cellular processes involved in the mitogenic response including protein synthesis, translation of specific mRNA species, and cell cycle progression from G1 to S phase. Northern and Western analyses revealed that amplification of this gene was accompanied by corresponding increases in mRNA and protein expression, respectively. These data represent the first determination of a gene amplification within 17q22-24 in breast cancer and suggest an oncogenic activity for PS6K.

Breast Neoplasms↗

PubMed1999

Efficacy of bilateral prophylactic mastectomy in women with a family history of breast cancer.

BACKGROUND: Options for women at high risk for breast cancer include surveillance, chemoprevention, and prophylactic mastectomy. The data on the outcomes for surveillance and prophylactic mastectomy are incomplete. METHODS: We conducted a retrospective study of all women with a family history of breast cancer who underwent bilateral prophylactic mastectomy at the Mayo Clinic between 1960 and 1993. The women were divided into two groups - high risk and moderate risk - on the basis of family history. A control study of the sisters of the high-risk probands and the Gail model were used to predict the number of breast cancers expected in these two groups in the absence of prophylactic mastectomy. RESULTS: We identified 639 women with a family history of breast cancer who had undergone bilateral prophylactic mastectomy: 214 at high risk and 425 at moderate risk. The median length of follow-up was 14 years. The median age at prophylactic mastectomy was 42 years. According to the Gall model, 37.4 breast cancers were expected in the moderate-risk group; 4 breast cancers occurred (reduction in risk, 89.5 percent; P<0.001). We compared the numbers of breast cancers among the 214 high-risk probands with the numbers among their 403 sisters who had not undergone prophylactic mastectomy. Of these sisters, 38.7 percent (156) had been given a diagnosis of breast cancer (115 cases were diagnosed before the respective proband's prophylactic mastectomy, 38 were diagnosed afterward, and the time of the diagnosis was unknown in 3 cases). By contrast, breast cancer was diagnosed in 1.4 percent (3 of 214) of the probands. Thus, prophylactic mastectomy was associated with a reduction in the incidence of breast cancer of at least 90 percent. CONCLUSIONS: In women with a high risk of breast cancer on the basis of family history, prophylactic mastectomy can significantly reduce the incidence of breast cancer.

Adolescent↗

PubMed1999

Mutation and expression analysis of the p73 gene in prostate cancer.

BACKGROUND: p53 is the most highly mutated tumor suppressor gene in human cancers. Recently, p73, a first homologue of p53, was identified and considered to be an imprinted tumor suppressor gene. Thus, we analyzed the possible role of p73 in human prostate cancers. METHODS: We investigated the expression levels and expressed allelotypes and searched for mutations in the p73 gene in 27 primary prostate cancers with matched normal tissues as well as in four prostate cell lines. RESULTS: Allelic expression analysis using polymorphisms in exons 2 and 5 revealed that p73 is biallelically expressed in both normal and tumor tissues, suggesting that p73 is not imprinted in prostate tissues. Quantitative PCR demonstrated that p73 expression is the same in both normal and tumor prostate tissues. Denaturing high-performance liquid chromatography and DNA sequencing revealed that there were no tumor-specific mutations in the p73 gene at the genomic level. CONCLUSIONS: These data indicate that alterations of p73, including mutations, changes in message abundance, and changes in allelic expression, are likely to be rare in early-stage prostate cancer, and that p73 could be a tissue-specific imprinting gene.

DNA Mutational Analysis↗

PubMed1999

Loss of markers linked to BRCA1 precedes loss at important cell cycle regulatory genes in epithelial ovarian cancer.

Advanced-stage epithelial ovarian cancers (EOC) from 114 patients were assessed for loss of heterozygosity (LOH or allelic imbalance) at several tumor suppressor gene loci as an initial step in identifying gene alterations important to the development of these tumors. The highest frequency of loss, 84% (86 of 102 cases), was observed for markers mapping near or within BRCA1; other significant frequencies of LOH were observed for loci mapping near or within CDKN2A/CDKN2B (56%), BRCA2 (61%), RB1 (67%), or TP53 (73%). No instance of TP53 LOH was observed without simultaneous allelic imbalance at the BRCA1 region (P = 0.0005). LOH of CDKN2 without loss near the BRCA1 region was seen in only 2 of 75 cases (P < 0.0001), and RB1 LOH without BRCA1 loss occurred in only 1 of 35 tumors (P = 0.0703). These data suggest that LOH of BRCA1, or a closely linked locus, precedes the loss of CDKN2, TP53, and RB1, and imply that inactivation of a tumor suppressor gene in this region is an important early step in the development of these tumors.

Adult↗

PubMed1999

The human glia maturation factor-gamma gene: genomic structure and mutation analysis in gliomas with chromosome 19q loss.

Human glia maturation factor-gamma (hGMF-gamma) is a recently identified gene that may be involved in glial differentiation, neural regeneration, and inhibition of tumor cell proliferation. The gene maps to the long arm of chromosome 19 at band q13.2, a region that is frequently deleted in human malignant gliomas and is thus suspected to harbor a glioma tumor suppressor gene. Given the putative role of hGMF-gamma in cell differentiation and proliferation and its localization to chromosome 19q13, this gene is an interesting candidate for the chromosome 19q glioma tumor suppressor gene. To evaluate this possibility, we determined the genomic structure of human hGMF-gamma and performed mutation screening in a series of 41 gliomas with and without allelic loss of chromosome 19q. Mutations were not detected, which suggests that hGMF-gamma is not the chromosome 19q glioma suppressor gene. However, the elucidation of the genomic structure of hGMF-gamma may prove useful in future investigations of hGMF-gamma in the normal adult and developing human nervous system.

Adult↗

PubMed1999

A pseudoepidemic of postoperative scleritis due to misdiagnosis.

OBJECTIVE: To describe a pseudoepidemic of infectious scleritis following eye surgery. METHODS: Retrospective cohort study with selected procedural and laboratory investigations. RESULTS: Twenty-one patients with postoperative scleritis were identified during a 2-month outbreak. Neither an infectious etiology nor a causative pre-, intra-, or postoperative exposure was found. The clinical findings, when carefully reviewed, were consistent with poor surgical-wound closure. CONCLUSIONS: The art of clinical diagnosis involves the subjective interpretation of clinical history, physical findings, and laboratory results. A repeated error in the interpretation of clinical findings can simulate an outbreak of disease. Clinicians may be reluctant to concede misdiagnosis.

Adult↗